Saturday, May 31, 2008


Completed envelope.

  • socketed Q39

Tests OK.


Belated completion of

  • all ICs socketed (except the 2SC536F's, there are too many of them!)
  • switched 'mome rath' mod (R46/R97)

Tested OK.

Sunday, May 18, 2008


Completed the VCO.

  • header on J4
  • all rare ICs socketed
  • Q8 socketed
Saw and square waves successfully viewed on CRO. All other build tests OK.

Sunday, May 11, 2008

first you get the money...

Finished the power section today.

This was all pretty much by-the-book except for:
I had trouble getting the correct voltage range out of TM6/IC22; 5.01 - 5.35V rather than the suggested 5.25 - 5.75V. I completed the section and managed to tune the required 5.33V on J4 so I guess that will be OK.

Test results during construction:
  • power jack 11V AC
  • C3 14.7V DC
  • C5 15.1V DC
  • IC20 5.05V DC
  • C1 5.98V DC
  • J4 5.33V & 11.83V DC

Saturday, May 10, 2008

all present and correct

All the components have now arrived. Packages from Adafruit, Mouser, Jaycar and Digikey.

Let's get started!

Monday, May 5, 2008

"more pronounced resonance"

Whilst awaiting the arrival of the remainder of my components I measured the gain of my, 100 or so, 2SA733P transistors.

According to the x0x m0ds page, high gain transistors should more accurately reproduce the "more pronounced resonance" of the original 303.

Quite a lot made it over the 300 mark. I will use the highest values for Q10, Q9 & Q8.

First Post

This weblog will, initially, serve to document my x0xb0x build experience.

As the kits are currently, and possibly forevermore, hard to come by, I am sourcing all the bits myself.

I may describe some of my other interests here at a later date.

On with the show...